There appears to be a lot of information posted about simul rappelling [and the potential dangers of it], but relatively small amount of information about tandem rappelling. It seems from information available that most people consider this only as a rescue technique, but I don't understand why. This will be a clearly biased post, but it is quite possible that I have missed many of the cons.

To be clear, I differentiate "standard rappelling" as a single person moving down 1 or 2 ropes with a single device, "simul rappelling" as two people moving down a single strand while counterbalanced by the other person, and "tandem rappelling" as two (or more?) people rappelling off a single device.

SpeedSetting up a tandem rappel does not take much longer than a standard rappel, but allows both people to descend at one time. It seems there would be similar speeds as simul rappelling.

CommunicationAs both rappelling would be together, there would be no chance of poor communication. This is contrast to standard rappelling, where rappelling in the dark/a storm with only one headlamp to share and too much noise to hear well could be quite the epic. Again, this is similar to simul rappelling.

SafetySince both people are on one device, either person can control the rappel [if an autoblock is used and is in reach of both people]. In case one rappeller needs hands free for any activity, the rappel can be controlled by the other person. This could be gear cleaning, sorting out the ropes, etc.

If for some reason, a person were to become injured / got hit by a rock, the other rappeller could handle the remaining descent.

For instruction / new climbers, tandem rappelling would also allow a more experienced person to keep a close watch and give advice while next to their newer climber.

In comparison, simul rappelling requires two experienced people. It requires complete trust in the abilities of the other person to act competently as a counterweight.

Standard rappelling requires each person to be competent. Exceedingly rarely, an issue may occur and the rappeller can be quite far from the partner [eg repeated question of how to save your partner if he's autoblocking or jamming the rope below you].

Anchor / Gear DemandsTandem rappelling clearly increases the force on the anchor, ropes, and device. It is hoped that nobody has to rappel off anything that is weak, but standard rappelling seems better if this is a question. Simul rappelling also has two people's weight on the anchor.

Tandem rappelling also requires only one rappel device, though this usually only becomes handy if a partnership drops one of their devices [and doesn't want to use a munter]. It does, however, require either some slings or cord to attach both people to one device.

--

This is a very one-sided post. I do appreciate your feedback on whether or not this is a good technique, or issues I may have overlooked.

You make some good points, but I think if you try tandem rappelling much you will relegate back to a rescue technique. The biggest con is that it is very difficult to move sideways should the next rappel anchor not be directly on the fall line. Also, it is just plain annoying rappelling with someone in your lap.

When an experienced climber is rappelling with one or two less experienced partners, stacking the rappel is the best solution. Basically, put the less experienced climbers on rappel, then the more experienced climber goes on rappel beneath them. The more experienced climber reaches the anchor and provides a fireman's belay for the remaining rappellers. I'm sure you can find more information about this technique in the archives here.

Every one of those 'advantages' is totally unnecessary if you can competently rappel.

You also see to ignore the massive disadvantage of an incredibly awkward rappel. Awkwardness is blatantly dangerous if not performed carefully and slowly which pretty much nullifies any 'advantages' you list.

Foolish wrote:

Since both people are on one device, either person can control the rappel [if an autoblock is used and is in reach of both people].

I'm not sure why you would use an autoblock & two people controlling the rappel. That is just absurd!

In reply to:

Standard rappelling requires each person to be competent.

Totally false. It is not difficult to safely rappel with one or several totally inexperienced people using standard rappelling techniques. I have done this on countless occasions.

In reply to:

Exceedingly rarely, an issue may occur and the rappeller can be quite far from the partner [eg repeated question of how to save your partner if he's autoblocking or jamming the rope below you].

Again you seem to fail to understand the basics of rappelling and managing those less experience than you.

you never leave your eggs in one basket and there no pros on speed rappelling other than getting yourself killed.

the only time you want any type of simul or tandem rap is when you are in a serious life and death situation where every second counts. example of that would be stuck on the wall with possible upcoming avalanche or rockfall (On, K2, Denali,Himalayas,..... ) with several people needed to rap off the ledge fast . I do not see that happening with most of these weekend rock climbers under a blue sky with bomb proof routs.

the only time you want any type of simul or tandem rap is when you are in a serious life and death situation where every second counts. example of that would be stuck on the wall with possible upcoming avalanche or rockfall (On, K2, Denali,Himalayas,..... ) with several people needed to rap off the ledge fast . I do not see that happening with most of these weekend rock climbers under a blue sky with bomb proof routs.

Not entirely true regarding simul rapping. There are some areas/towers where there are no top anchors. The rope is placed across the top (in a spot where it won't roll off) and the two climbers simul rappel down opposite sides of the formation. This is more common than you think in the Needles of South Dakota.

Tandem raps suck. We tried it once after I dropped my ATC, it was not fun. I can't imagine how awkward that would be with one of the party injured. I used a Munter for the remaining raps, and although it did kink the rope more than I would ever have believed, it was still far better.

the only time you want any type of simul or tandem rap is when you are in a serious life and death situation where every second counts. example of that would be stuck on the wall with possible upcoming avalanche or rockfall (On, K2, Denali,Himalayas,..... ) with several people needed to rap off the ledge fast . I do not see that happening with most of these weekend rock climbers under a blue sky with bomb proof routs.

Not entirely true regarding simul rapping. There are some areas/towers where there are no top anchors. The rope is placed across the top (in a spot where it won't roll off) and the two climbers simul rappel down opposite sides of the formation. This is more common than you think in the Needles of South Dakota.

if you can place the rope on top then you can easily rap with one person with two stands of rope ( assuming you carry atc or 8 on you). in the last few years few people have died falling on simul rap so again, what is your life worth !!!

if you can place the rope on top then you can easily rap with one person with two stands of rope ( assuming you carry atc or 8 on you).

No, you're not understanding. On a number of the Needles spires, there are *NO* anchors on top. The leader slings or more usually ties off the top of the spire with the rope, which, along with the leader's stance and mass, forms the anchor to bring up the second. Since the leader is often part of the anchor, it's essential that they belay off their harness.

For descent, the rope is laid across the top of the spire, usually in some sort of natural groove or notch to prevent it from rolling off, then the party simul-raps down opposite sides of the spire.

the only time you want any type of simul or tandem rap is when you are in a serious life and death situation where every second counts. example of that would be stuck on the wall with possible upcoming avalanche or rockfall (On, K2, Denali,Himalayas,..... ) with several people needed to rap off the ledge fast . I do not see that happening with most of these weekend rock climbers under a blue sky with bomb proof routs.

Not entirely true regarding simul rapping. There are some areas/towers where there are no top anchors. The rope is placed across the top (in a spot where it won't roll off) and the two climbers simul rappel down opposite sides of the formation. This is more common than you think in the Needles of South Dakota.

if you can place the rope on top then you can easily rap with one person with two stands of rope ( assuming you carry atc or 8 on you). in the last few years few people have died falling on simul rap so again, what is your life worth !!!

Majid, you're not getting it. The Needles towers he is referring to have no top anchor and no place to anchor the rope so that both strands hang on the same side. You have to hang the rope with one strand off of each side of the tower and simu-rappel off of opposite sides of the tower. I have only come accross this a couple of times and only at the Needles in SD (not that it doesn't occur elsewhere).

Tandem rapping sucks! it's good for rescues, but that's it. I like simul rapping and find it to be useful when you need to get down quickly. I broke a bone in my hand on a route one time (right, dominant, hand) My partner wanted to tandem rappel down so that I wouldn't have to hold the brake strand. (It was 3 double rope rappels to the deck) I declined and rapped with my left hand and a prussic backup. I think I'd have to be unconscious or non functional before I hung off my buddy's crotch. Now if it'd been the cute girls behind us...

Another area were (I think) simul-rapping makes sense is in loose chossy areas. Last summer we were rapping after getting off route, climbing in the Alps, and into some incredible loose rock (i.e. impossible to rap with out knocking loose quite a few good sized rocks (up to softball size). As it was nearly impossible to rap and then get out of the path of falling rocks it made sense to rap down together.

Tandem rapping is awkward and uncomfortable. On broken ledgy terrain about twenty times more awkward and uncomfortable.

Having hit the ground considerably faster than desired during/after a tandem rap its worth noting that it is essential the device has enough power to cope with the weight of two climbers!Lowering the first climber is a better, faster and safer solution to most of the problems you describe.

This is the point to consider. And lowering has been my plan of action for most of the aformentioned problems. Now with the SD Needles, I'm going to loop a sling.

Which the locals will consider unsightly trash and an affront to their rather strict ethics. They'll rightfully point out that the route and descent has been done by multitudes without resorting to leaving trash and that if you can't handle it, you shouldn't do the route.

I use the tandem rappel quite often on canyoneering trips, but mostly only with little kids that are too light or scared to rap on their own. It would suck doing it with someone my size and I ve never done it with anyone over 100 lbs.